I am skinning a skewed quad with math
for x in range(8):
    for y in range(8):
        p1 = v1.lerp(v2, x/len[array])
        p2 = v4.lerp(v3, x/len[array])
        p3 = p1.lerp(p2,y/len[array[x])
        this is the point I needed